The problem with stairs and ladders is that you have individually created each step, with gaps in between. It would not only be easier, but also a lot more convenient, if you changed it so that the actual thing the character runs up is a completely flat surface that is just rendered with see-through parts for gaps between stairs. In BD, the ladders to get to the mine area cause you to have to switch run mode on and try an jump from rung to rung. Replace it with a steep, flat surface with coded to allow players to walk on it despite the steep incline, paint the texture with invisible parts and there you go, problem solved